Clinical Outcomes of Robotic Versus Laparoscopic Assisted Radical Gastrectomy for Advanced Siewert II/III AEG

Inclusion Criteria: * Age from over 18 to under 75 years * Primary gastric adenocarcinoma (papillary, tubular, mucinous, signet ring cell, or poorly differentiated) confirmed pathologically by endoscopic biopsy * cT2-4a(clinical stage tumor), N-/+, M0 at preoperative evaluation according to the American Joint Committee on Cancer (AJCC) Cancer Staging Manual 8th Edition * Expected to perform total gastrectomy with D2+No.19+No.20 lymph node dissction to obtain R0 resection sugicall results. * Performance status of 0 or 1 on ECOG (Eastern Cooperative Oncology Group) scale * ASA (American Society of Anesthesiology) class I to III * Written informed consent Exclusion Criteria: * Women during pregnancy or breast-feeding * Severe mental disorder * History of previous upper abdominal surgery (except laparoscopic cholecystectomy) * History of previous gastric surgery (except ESD/EMR (Endoscopic Submucosal Dissection/Endoscopic Mucosal Resection )for gastric cancer) * Gastric multiple primary carcinoma * Enlarged or bulky regional lymph node （diameter over 3cm）supported by preoperative imaging * History of other malignant disease within the past 5 years * History of previous neoadjuvant chemotherapy or radiotherapy * History of unstable angina or myocardial infarction within the past 6 months * History of cerebrovascular accident within the past 6 months * History of continuous systematic administration of corticosteroids within 1 month * Requirement of simultaneous surgery for other disease * Emergency surgery due to complication (bleeding, obstruction or perforation) caused by gastric cancer * FEV1\<50% of the predicted values